1. Field of the Invention
The present invention relates to a color liquid crystal apparatus using a liquid crystal display device for displaying colors according to applied voltages, and a method of driving the same.
2. Description of the Related Art
Ordinary color liquid crystal display (LCD) devices are equipped with color filters for three primary colors so that the intensities of lights passing the color filters are controlled to provide arbitrary display colors.
LCD display devices equipped with color filters suffer dark display because light is absorbed by the color filters. The LCD devices are therefore inadequate as reflection type LCD device devices.
A birifringence control type LCD device is known which can present a plurality of colors without using color filters. The birefringence control type LCD device comprises an LC cell obtained by sealing liquid crystal, subjected to an aligning treatment, between a pair of electrodes-formed substrates, and two polarization plates so arranged as to sandwich the LC cell.
The birefringence control type LCD device alters the molecular alignment of the liquid crystal by applying an electric field to the liquid crystal, so that the spectrum distribution of the light leaving a pair of polarization plates is changed, thereby displaying the desired colors.
Since the birifringence control type LCD device presents bright display, it can be realized as a reflection type color LCD apparatus. This birefringence control type LCD device also has an advantage of having a simple structure.
But, the colors displayable by the conventional birefringence control type LCD device are determined by the applied voltages. Therefore, the types or number of displayable colors is limited to the number of the applied voltages so that a difference is likely to occur between the desired display color and the actually displayed color. Further, increasing the types of applied voltages to increase the number of display colors result in greater consumed power.
Even the colors displayable by controlling the applied voltages may not be displayed stably because the ranges of the applied voltages that are used to display those colors are narrow or the alignment of the liquid crystal becomes unstable.